In recent years, research on organic materials having high functions and high performance that exceed the characteristics of inorganic materials has attracted attention, and organic devices of the next generation have been developed. In order to achieve this, the development of new organic materials is absolutely indispensable, and in fields such as applied chemistry, molecular steric structure is determined by structural analysis of newly synthesized materials, and the functions of these materials are inferred. Furthermore, post-genome research known as proteome has been actively pursued. Something that has attracted particular attention is research that is referred to as “structural genome science,” which attempts to elucidate the three-dimensional structure of proteins. Elucidation of the structures and functions of proteins is directly connected to the treatment of diseases and the creation of drugs, and is therefore expected to have merits that lead to the elucidation of life phenomena. When the structures and functions of various organic materials are analyzed, there are often cases in which measurements are performed not at an ordinary temperature, but by cooling the object of analysis to a low temperature. X-ray crystal structure analysis, which is one of the important means for analyzing the detailed steric structures of organic materials, may be cited as a representative example of such analysis.
In order to apply X-ray crystal structure analysis, single crystals of organic materials that are the object of analysis are required. There are instances in which measurements are performed in a state in which crystals are cooled in order to prevent damage to the organic crystals caused by irradiation with high-intensity X-rays. In cases where extremely brittle crystals such as protein crystals are the object of analysis, in particular, crystal structure analysis is generally performed in a cooled state (at an extremely low temperature of −150° C. or lower) by means of a low-temperature gas such as nitrogen.
The measurement precision of the X-ray crystal structure analysis is affected by the quality of organic crystals that are the object of analysis, the presence or absence of adhering matter around the crystals, and the like. In order to perform measurement with high precision, single crystals of good quality that have a desired shape are necessary. However, since crystallization conditions and growth conditions for obtaining good-quality single crystals have not been established for most organic materials, crystal preparation is extremely difficult. Moreover, even if crystallization is successful, trouble occurs in terms of targeted measurement in that single crystals cannot be obtained, there are problems in crystal quality, etc. Furthermore, solution adhering to the periphery of the crystal, substance holding the crystal, and the like become factors which lower the measurement precision.
Accordingly, there are cases in which the following types of working are required: namely, organic crystals constituting the object of analysis are adjusted to a shape that is appropriate for X-ray crystal structure analysis, only portions with good crystal quality are extracted, adhering matter or the like that is unwanted for the measurement is removed from the crystal surfaces, etc.
However, since crystals of organic materials are softer and more brittle than crystals of inorganic materials, damage such as cracking and splitting occurs in peripheral parts if a large impact is applied during working. Of these crystals, biomolecular crystals such as protein crystals and macromolecular crystals that are handled in supramolecular chemistry belong to an especially soft category of organic crystals; accordingly, handling is extremely difficult. Currently used working methods for organic crystals are working methods that require mechanical contact with these crystals. However, these methods have major problems in terms of working precision or the like.
Furthermore, the mechanical working methods described above are premised on working at ordinary temperatures, and it has been extremely difficult to adapt such methods to working under low-temperature conditions in which the object of working is frozen. Accordingly, in cases where there was a need for working following the cooling of organic crystals to a low-temperature state, the only handling method available so far was to first return such organic crystals to an ordinary temperature and then to perform working. However, by subjecting organic crystals over and over to a large temperature change from a low temperature to an ordinary temperature or from an ordinary temperature to a low temperature for the purpose of performing working, organic crystals are damaged, or irreversible structural alteration occurs, so that there are cases in which desired measurement cannot be performed.